Concrete mixer construction



Nov. 3, '1942. G. Rr DoDs'olN y 2,300,490

CONCRETE. MIXER CONSTRUCTION Ly Q C Il i s R INVENTOR. .gx u, Mmm N N 3% l ATTORNEY Nov. 3, 1942. l G. R. DQDSON 2,300,490v

CONCRETE MIXER CONSTRUCTION Filed April 23, 1941 2 sheets-sheet 2 t\ w 'n v IN VEN TOR. G, @pods af?,

ATTORNEY Patented Nov. 3, 1942 narran STATES parametrica 2,300,490 Y coNcRE'rE MIXER CONSTRUCTION Glenn R. Dodson, Wichita, Kans. Application April 23, 1941, Serial No. `389,863 2 claims. (ci. 25a- 145) The present invention has relation to apparatus for mixing materials such as concrete and the like, and aims to provide an improved construction which is not only of a sturdier and simpler design, but also cheaper and more economical as regards repair and maintenance costs.

The improved construction comprises end frame structures of simple design and unusual strength having `the base and end portions of the mixing drum forming a unit at each end of the apparatus.

An outstanding feature of importance in the improved construction is the provision of a mixing drum with replaceable or renewable segments adapted for ready and convenient replacement as becomes necessary, and thereby greatly reducing the cost of repairs over the comparative costs of the conventional type of apparatus for such operations.

It is also sought to provide a mixing apparatus of the character indicated in which the limproved renewable segments of the drum structure are so designed as to be interchanged or shifted for distributing the wear due to the mixing operation, and also to eliminate the outside sheet metal drum or housing commonly forming a part of such mixing apparatus.

With the foregoing as well as various other minor features of improvement in view, the invention. will now be described by reference to the accompanying drawings illustrating one desirable form of construction which has been found suitable for the embodiment of the aforesaid improvements, after which those features and combinations deemed to be both novel and patentable will be particularly set forth and claimed.

In the drawings- Figure l is a side elevation illustrating a mixing apparatus embodying the present improved features of construction;

Figure 2 is an endv elevation of the same, omitting the drive pulley and showing its drive shaft in section, and with dotted lines representing the discharge gate moved into open position;

Figure 3 is a transverse sectional View, representing a section taken on the line 3 3 of Figure 1;

Figure 4 is an enlarged sectional detail view, representing a section taken on the line 4%-4 of Figure 2;

Figure 5 is a fragmentary elevation on a larger scale showing a portion of the segmental structure of the mixing drum; and

Figures 6 and 7 are sectional detail views rep- 55 resenting sections taken on the section lines 6 6 and 'I-l, respectively, of Figure.

Referring now to the vdrawings in detail,- each end of the apparatus is illustrated as comprising a base or supporting member I and a vdrum end or head member, which are cast as integral units, thus providing a strong and rigid construction as well as a neat design and exterior nish for the opposite ends of the apparatus. Each drum end or head member is of shallow cylindrical form, thus providing a at disk or drum head I2 and alsoy a cylindrical body I2 to which the adjacent ends of the drum segments I4 may be secured, as by means of bolts I5 and nuts I6, as clearly illustrated in Figures 1,- 4 and 7.

These drum segments I4 are forthe most part of standard and uniform size, being of relatively narrow width and of cast construction relieved and lightened by the series of spaced recesses I8. Moreover each segment is formed at its middle portion with a-lug or finger projection 20 extending into overlapping relation with the middle portion of an adjoining segment, to which it is securely fastened by means of a bolt 2I and nut 22,-the head portion of the bolt being preferably countersunk in the inner face of one of the segments, as clearly shown inrFigure 6.

This overlapping lug or finger construction eiectually prevents bulging out of the slats or segments at the middle portion of the mixer drum; and it is apparent that any one of the segments may be removed or replacedbysimply removing the bolts I5 at its endsand the bolts 2I securing it to the next adjoining segments, in van obvious manner. Y

Each base or supporting member I0 is equipped with a bearing bracket 25 to provide bearings for the opposite ends of an axle shaft 2'1 extending centrally Vthrough the Adrum heads vIZ and hence axially through the mixing chamber formed by the drum structure above described. To this axle. shaft-27 is secured, by means of clamping yokes 28 and' bolts 30, a series of radial arms 32 (see Figure 3) carrying spiralbladesl33 design-ed to serve as mixing paddlesV for stirring the contents of the drum or mixing chamber as the axle sha-ft is rotated in the mixing operation.

To one end of the shaft 21 is secured a large gear wheel 35, the upper portion of which may be provided with a suitable fender or guard member as indicated at 36 in Figure 1. This gear wheel 35 meshes with a drive pinion 31 which is mounted on one end of a countershaft 38 journaled in bearings 40 supported by the base or supporting members IB. The other end of the countershaft 38 isequipped with a belt drive pulley 42 for power operation, and also a conventional form of clutch assembly 43 for convenient control of the drive connections.

The top of the mixing chamber formed by the drum structure is partly open as indicated at 45 in Figure 3, for supplying the batch of material to the mixing chamber; and this opening 45 may be spanned by a grating or grill 'framework 41 which is hinged to brackets 43 at one side of said opening 45 (see Figures 2 and 3).

The lower portion of the drum structure and to one side of center, is provided with a discharge opening 49 of appropriate size and Vcontrolled by a gate member `50 which is secured to a suitable framework 5l pivotallysupported by suspension links 52 carried by a rod 53 journaled in brackets 54 above said discharge opening. The opposite ends of the framework 5| are connected to the ends of irregularly shaped arms 51 extending to the opposite side of the apparatus, where they are pivotally connected to crank arms 58 attached to a longitudinal shaft 60 which is journaled in bearings l62 and also provided with an operating arm or handle 64 for throwing the arms 51 into and out of gate-opening position, as illustrated in Figure 2.

With a construction of the character above described, it will be apparent that the integral supporting frames and drum heads or end members provide a neat, compact and sturdy construction for the opposite ends of the apparatus, including the cylindrical end bodies l2 for facilitating the mounting and securing of the en-ds of the duplicate slats or drum segments and thereby carrying out the main purposes of the invention. The usual type of mixer in this class has always required what are known as outside sheet metal drums and intermediate lining and reinforcing segments for replacement from time to time. Such replacement has always been more or less awkward and diicult, and .correspondingly expensive. But in the present improved construction there is no continuous metal drum member with reinforcing segments, but only the segmental drum construction itself receiving all the Wear and comprising segments which in themselves constitute the only parts to be removed or adjusted or replaced, an operation which carried out by means of the bolts at the ends of the segments and those connecting adjoining segments. Obviously, the construction is such as also to enable the shifting of the segments from time to time, since -those at the bottom of the mixing chamber are subject to the most wear and may be replaced, as required, by interchanging them with the upper segments .which undergo relatively less wear. In addition, the feature of the securing means between adjoining segments, in the form of the projecting lugs or fingers, overlapping and bolted in place, affords effective provision for firmly holding the middle portion of the drum structure against deflection and bulging under high mixing pressure, thereby dispensing with any bands or hoops around lthe middle section of the drum or mixing chamber.

The improved form of apparatus also provides convenient and easy means of control for the discharge gate, with a very sensitive action due to the operation of the crank arms 58 by a movement past center o'f the shaft 60, and hence with a minimum of effort necessary for controlling the gate movement.

It will therefore be seen that I have devised a practical and efficient arrangement and construction of apparatus suitable for the embodiment of the various improvements described in the foregoing; and while I have illustrated what I now regard as the preferred form of construction for the purpose, I desire tobe understood as expressly reserving the right to make all changes or modifications which may fairly be deemed to fall within the spirit and scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters-Patent is:

l. Concrete mixing apparatus, comprising fixed end supporting members carrying drum end or head members, and longitudinal drum segments connecting said drum end or head members and cooperating therewith to form a stationary mixing chamber, the middle portion of each of said drum segments having a finger lug or projection extending into exterior overlapping relation to the middle portion of an adjoining drum segment and being bolted thereto in countersunk relation to the interior surface of the segments and the latter being flush and `smooth throughout the interior of the mixing chamber, the opposite ends of said drum segments being removably secured to the peripheries of said drum end or head members.

2. A concrete mixer construction comprising a pair of fixed end supporting members, each formed with a base standard or supporting portion and also an in-tegral drum head member composed of a hollow `cylindrical portion closed at one end to form a flat disk element in slightly offset relation to the main upright supporting portion of the standard, said drum head members projecting toward each other from the upper ends of said supporting portions and in alinement whereby said disk elements serve as drum ends or heads for a stationary mixing chamber with the open ends of said hollow cylindrical portions facing in opposite directions, a plurality of longitudinal segments cooperating with said nat disk elements to form a stationary mixing chamber and having the opposite ends of said segments secured exteriorly to said hollow cylindrical portions of the drum head members, and bolt elements securing said segments to said drum head members and having the opposite ends of said bolt elements engaging the outer faces of said segments and the interior faces of the open ends of said hollow cylindrical portions of the drum head members.

GLENN R. DODSON. 

